Scientists at the Krembil Neuroscience Centre have made a groundbreaking discovery in the lab -- how to prevent the death of brain cells which would normally die within a few days after the brain is deprived of oxygen, such as following a cardiac arrest.
Scientists have identified how to selectively block a protein called TRPM7, which causes cell death in the area of the brain that is responsible for higher mental functions, including learning, memory and emotion (the hippocampus).
This was achieved by using a gene therapy approach in animal models in which the researchers infected the hippocampus with viruses containing genetic instructions that impeded the production of TRPM7. This protein was initially discovered by the same researchers at the Toronto Western Hospital as being responsible for cell death after oxygen deprivation.
"We are excited by this very promising research as it leads us a step closer to better care for millions of people worldwide who are affected by strokes," said principal investigator Dr. Michael Tymianski, Director of the Neurovascular Therapeutics Program at University Health Network. "Once brain cells die, the damage is irreversible and patients are left with life-long disabilities."
In cardiac arrest victims, the lack of oxygen and blood flow to the brain can lead to the death of brain cells in the hippocampus. This can result in impaired cognition and profound neurological impairments within days of experiencing a cardiac arrest. The hippocampus is located in the temporal lobes (lower, back part) of the brain. The hippocampus is especially sensitive to reduced oxygen in the body and periods of oxygen deprivation may result in damage to this region of the brain.
This research is ground breaking in part because there are currently no drugs available to prevent this type of brain damage during or following a stroke in which the whole brain is deprived of oxygen, such as after a cardiac arrest. This early step to preventing such brain damage could aid in the development of new drug therapies that would prevent some of the devastating effects of strokes. However, the findings of Dr. Tymianski's team could have implications for patients with Alzheimer's and Parkinson's disease as well as for several other disorders such as heart attacks, in which cells die after they are deprived of oxygen.
Dr. Michael Tymianski is a neurosurgeon at the Krembil Neuroscience Centre specializing in neurovascular diseases, Director of the Neurovascular Therapeutics Program at the University Health Network and is a senior scientist at the Toronto Western Research Institute.
Read this story at the Globe & Mail website.
